Engine-valve-operating means



May 27, y1930. IW. A. wocn ENGINE VALVE OPERATING MEANS 3 Sheets-Sheet l Filed Dec. 1o. 192s' D /lllll [lill/(4 isfi Medy

INVENTOR ATTOR N EYS May 27, 1930. l vw, A woon 1,760,853

ENGINE VALVE OPERATING MEANS Fired Dec;- 1o. 192s :s sheets-sheet 2 ATTORNEYS May 27, 193D. W. A. WOOD 7 ENGINE VALVE OPERATING MEANS y Filed Dec. 10. 1928 3 Sheets-Shet 3 ATTORNEYS Patented May 27, 1930 UNITED STATES PATENT OFFICE WALTER A. WOOD, OF FLINT, MICHIGAN, ASSIGNOR T GENERAL MOTORS RESEARCH CORPORATION, 0F DETROIT, MICHIGAN, A CORPORATION OF DELAWARE. I

Application led December lO, 1928. Serial No. 325,061.

This invention relates to an arrangement for operating valves hydraulically, and is designed especially for use with internal com bustion enginesused on automobiles.

It is well lmown that mechanical valve gear must be adjusted so that there is a slight .amount of clearance between the parts when cold so that after the engine has been running a while and the parts become heated and eX- 1'0 pand, the expansion will simply take up the clearance,and allow the valves to seat properly. Even with perfect adjustment the valves will be quite noisy until the engine warms up owing to the clearance which must be ro- `vided. However, most of the time the adjustment will be far from perfect so that there will always be a certain amount of clearance l and the resulting impact of the tappet on the camshaft, the valve on its seat, and the intermediate parts of the valve operating gear on each other will produce objectionable noise. My im roved hydraulic valve gear is of the type in w ich a source of fluidunder pressure is provided, and rovision is made for directing the iuid to t e valves in proper sequence to effect their unseating. My gear consists of a uid pump, a series of hydraulic chambers,

one for each valve, and a distributor for directing fluid under pressure from the pump to the chambers to operate the valves. My system is preferably a closed one, that is, it is so designed that the liuid after operating the valve is returned directly to theintake side of the pump. My design is also a very compact one. Thus the pump and distributor are mounted on a common axis andl the hydraulic chambers are arranged closel adjacent the distributor. The whole assem ly is designed I* sothat it may be formed as a single unit adapgted for ready attachment to the engme bloc f In the drawings:

valve engine equipped with my valve gear, parts being broken away to better show the construction. 2'

Figure 2 is a longitudinal section through a portion of the gear. f Figures 3 and 4 are sectional views through the center line of one of the valves taken at right angles to the section of Figure 2and 'showing one of the valves in seated and un-` seated positions.

Figure 5 is a view of the cover removed.

I have illustrated on the drawings a con ventional form of internal combustion cngine provided with a crankcase A', within which is journaled the usual crankshaft B, equipped with a iywheel contained within the housing C D represents the cylinder block formed to provide cylinders E, of which there may be any-desired number. F indicates the detachable cylinder head. The head is formed at each cylinder with the valve openf 65 ings, or ports normally closed by valves G and, H constituting the intake and exhaust valves respectively. The valves are provided with stems L slidably mounted in guides I, and are normall urged to closed position by means of suita le coil springs J. The parts so far described are conventional, the valve stems ordinarily being engaged either by overhead rocker arms operated by ta pets from the usual camshaft, or directly y an overhead camshaft to effect their opening 'and closing.

.According to my invention the mechanical valve I'operating gear is vdone away with, and

pump with the instead a hydraulic arrangement is employed.

head by 'means of brackets 11. The casing is closed at both ends, and contains within itsA main bore as clearly shown in Figure 2, a

rotary distributor 12 having at one end a rea5 duced extension 13 projecting outside of the casing, and carrying a sprocket 14 driven by chain 15 from sprocket 16 mounted upon the crankshaft B. By -this arrangement, it is obvious that the distributor will be driven in timed relation'to the crank shaft. At oppoy site sides the casing 10 is provided with intake I Figure 1 isa side elevation of an overhead" 12, and the gear 21 being mounted upon a i stub shaft 22 journaled within the casing 19, y which houses the pump. While I have pre- 10e ferred to illustrate the pump as mounted on the distributor and driven therefrom, it is obvious that this is not essential, the pump .simply representing one convenient source of distributor 12 is provided adjacent each of the hydraulic chambers 23 with a pair of grooves 28 and 29. The groove 28 cooperates with port 26 leading from the discharge manifold 17, andthe port leading from the distributor to the hydraulic chamber 23. When the groove 28. is in the position shown in Figure 4, oil is discharged from the manifold 17 through the port 26, groove 28, and

" the port 25 into the hydraulic chainber causf A ing the position shown in Fi and the valve spring J forces the fluid out' ,the reservoir will be filled with ing the piston 30 to be forced downwardly unseatin the valve as shown in Figure 4.-.- As will obvious froman inspection of Figure 4, this communication is established some time'prior tothe distributor 12 reachgure 4. During the entire period that this communication is established the valve G is heldJopen. If the valve be an intake valve during 'this period combustible mixture is supplied the cylinder E, if an exhaust valve, burnt gases will be carried away. Upon further rotation of the distributor, the groove 29 establishes communication between the port 25 leading to the hydraulic chamber and the port 27 leadingto the intake manifold 18. Upon this communication being established the pressure of the Huid on the piston 3() is relieved of the chamber through the port 25, groove 29, and port 27 into vthe intake manifold 18, hence it is conducted to the intake side of the gear pump.

The ooves 28 and 29 are so placed in the distributor that the valves are opened and closed in proper sequence in accordance with the iiring order of the engine.

Thecasing 10 will be provided with a suitable inlet for initially filling the system, and

if desired, this inlet may consist of a connection leading from the engine crankcase to the intake side of the pump to insure that times.

The described construction is very simple, K

and compact. It may be removed as a unit for inspection, or repair, andoobviously, by

- slight modification could be adapted to enl 1. In an engine, 'one or more cylinders 'each having intakev and exhaust ports, valvesf for controlling the opening and the closing of the ports, the valves having stems, a piston mounted on each valve stem, a casing extending longitudinally of the engine transversely of all of the cylinders thereof, the casing being formed with relatively small cylinders slidably receiving said pistons, the casing having a cylindrical bore and being formed with longitudinally extending intake and eX- haust manifolds communicating through ports with the bore, said bore communicatin with the .relatively small cylinders throng other ports, means for supplying liquid pressure to the intake manifoldand removing it from the exhaust manifold, and a rotaryv valve member within the casing having ports therein adaptedV to establish communication successively between the intake ports and the last named ports and between the last named ports and the second'named ports. 2. A fitting for hydraulic valve gear provided with spaced intake and discharge manifolds, hydraulic chambers between said manifolds, a distributing chamber communicat. ingwithsaid manifolds and said chambers,

land a distributor in said distributing chamber for controlling said communication.

3. A fitting for hydraulic valve gear provided with spaced intake and discharge manifolds, hydraulic chambers between said manives folds, a distributing chamber communicatin i with said manifolds and'said chambers, an

a distributor in said distributing chamber for controlling said communication, said fitting being provided at one'end with a pump chamber communicating withsaid manifolds, and a pump in said chamber.

4. A fitting For hydraulic valve gear provided with spaced intake and discharge manifolds, and with a pump chamber at one end communicating with said manifolds, a distributing chamber between lsaid manifolds and communicating therewith, a rotary distributor in the distributing chamber, a rotarypump in the pump chamber, said pump and distributor being connected together for rotation about a common axis.

In testimony whereof I aiiiX my si nature.

. WALTER'v A. W OD.'

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